This invention relates to a method and system for determining certain characteristics of porous material taken from subsurface formations and, more particularly, to a method and system for determining permeability of a core sample taken from a subsurface hydrocarbon-bearing reservoir by measuring the fluid volumes of a two-phase effluent fluid flow through the core sample.
In the production of an oil or gas reservoir, it is important to know certain lithological properties of the reservoir. One of the most important of these properties is the permeability of the reservoir rock in which the oil or gas is stored. Permeability is a measure of the ability of the reservoir rock to transmit fluids through pore spaces in the porous rock material and is inversely proportional to the flow resistance offered by the material. A core sample of a subsurface rock material is generally tested for permeability by forcing a fluid through the core sample, which has been previously saturated with the same fluid, and measuring the rate of flow of the fluid through the core sample.